This invention relates to the positioning of a synchronized picture at any desired location of the television raster including off the screen. This invention, more particularly, relates to such television positioning apparatus used with a television video synchronizer which is normally used for synchronizing the television signals.
These synchronizers have been introduced to synchronized broadcast sources to a local reference generator. A video synchronizer is an electronic unit that samples the analog input, converts it to a digital format, stores the digital data and operates on the digital data to deliver a desired analog output which is constructed from the sampled video. It is designed to automatically lock a nonsynchronous broadcast signal to a local reference generator and thus allow fully synchronous treatment of the incoming video for mixing the station programs. The nonsynchronous signal is digitized and stored in a memory. The input video signals are temporarily stored in the digital memory in predetermined nonvarying locations as prescribed by addresses from an address generator in such a way that reading the stored video out of the memory produces a video signal identical to the input video signal with the exception being that the timing of the output video is locked to the studio reference. The data is clocked out of the memory at a rate locked to the reference sync generator (usually the local station). This synchronizer isolates the input/output video lines and the output is fully synchronous in vertical, horizontal and color phases with the reference.
These video synchronizers make possible many special effects for relatively low additional cost. In a separate application entitled, "Television Picture Size Altering Apparatus" U.S. Pat. No. 4,134,128, filed Dec. 27, 1976, Robert N. Hurst describes the special effect of expansion or compression of the video by adding or eliminating samples stored in the digital memory. In a separate application entitled, "Television Picture Compressor" Ser. No. 862,180, filed Dec. 19, 1977, there is described a particular technique for reducing the size of a full frame or full field picture to a one-quarter size. Applicant's invention herein relates to the special effect of moving the reduced size or full size pictures on the displayed output.